Tailed Beasts
The tailed beasts (尾獣, bijū) are the nine titanic behemoths within the Naruto series. They are differentiated by the number of tails they have, ranging from one to nine. The tailed beasts are living forms of chakra, sometimes referred to as "Chakra Monsters" (チャクラのバケモノ, Chakura no Bakemono), giving them immense reserves of especially strong chakra that far outmatches most shinobi. The tailed beasts' chakra is coloured red. They also have the ability to communicate telepathically with each other and their jinchūriki, and possess several levels of consciousness. There is the initial level where the beast may appear in a habitat of sorts seemingly imprisoned in some way by whatever fūinjutsu that sealed them. The second level is where all the tailed beasts can convene, free of any restrictions and communicate with one another. The jinchūriki are also able to enter there, but in order to do so, they must be completely linked with their tailed beasts. The tailed beasts are also able to freely transfer their chakra to whomever they choose, and as Kurama has noted, is a less complicated process for them than it is for humans. Long ago before the founding of the hidden villages, during an era of endless wars between mankind, there existed the Shinju, a tree that was revered as a deity which bore a fruit once every thousand years. Although it was forbidden to consume the Shinju's fruit, it was eaten by Princess Kaguya Otsutsuki, who used the power it granted her to end the wars plaguing the lands. Some time after this, Kaguya gave birth to a son who became the first human born with chakra. Enraged by the theft of its power, the Shinju assumed a monstrous form of what many christened as the "Ten-Tails". The Ten-Tails rampaged throughout the lands until Kaguya's son managed to single-handedly defeat the beast and sealed it within himself. This act, along with many other great deeds throughout his lifetime, resulted in Hagoromo becoming revered as the "Sage of the Six Paths". Young Biju The young tailed beasts with the Sage of the Six Paths. However, knowing that his death would unleash the Ten-Tails back into the world to continue its rampage and reclaim the chakra that humanity now possesses, the Sage separated the monster's chakra from its body before using Chibaku Tensei to seal the husk in what would become the moon. From there, the Sage used his Creation of All Things ability to divide the chakra into nine fragments that are each given a physical form and name. Some time after their creation, the young tailed beasts were told that they were all still linked to one another despite being separate entities. The Sage also told them that would eventually become one again, yet not as they originally were, and that one shall appear at that time to show them what true power is. Despite their close relation to one another, there is a significant amount of friction between the tailed beasts that caused them to part ways. One such cause was due to Kurama's belief that their strength was determined by the number of their tails. Over the centuries, countless humans failed to see the tailed beasts as sapient individuals with their own personalities and emotions, and they treated them with great disdain and fear, but because of their immense power, they sought the tailed beasts out as mere tools to be used or taken, a sentiment they absolutely detest. By the time of the formation of the shinobi villages, after his victory against Madara Uchiha in the Valley of the End, Hashirama Senju, the First Hokage, used his Wood Release techniques to capture several of the tailed beasts and allow the other shinobi villages to purchase them in exchange for signing peace treaties with each other, in order to stabilise the balance of power between them. Madara, later revealed to have survived the altercation, had obtained Hashirama's DNA — his true purpose for the encounter. Integrating Hashirama's DNA into his wounds, Madara awakened the Rinnegan shortly before the end of his natural lifespan. With it, he was able to summon the vessel of the Ten-Tails from the moon. However, using artificial means to expand his life, Madara was unable to carry out his plan to revive the Ten-Tails. As such he passed on this task to a young Obito Uchiha who had come to share his view on the world after Rin Nohara's death. Ten-Tails rvived The Ten-Tails is revived. With the help of Akatsuki, by the time of the Fourth Shinobi World War, seven of the nine tailed beasts had been sealed into the statue. Irked by the slow progress of the plan, assuming the identity of Tobi to oversee the matters and converting reincarnated hosts into his personalised Six Paths of Pain, Obito accompanied by the statue entered the battlefield to obtain the Benihisago and Kohaku no Johei which contained the Gold and Silver Brothers. Despite not having sealed the last remaining two tailed beasts entirely — only possessing portions of their power, Obito decided to begin the plan as the Demonic Statue of the Outer Path undergoes a painful regeneration into the Ten-Tails. When Madara realised the situation, he attempted to rectify this. Despite Naruto and Killer B's attempt to destroy the Demonic Statue while in mid-transformation, it was successfully restored into the Ten-Tails, albeit in an incomplete form for a while before reaching its matured state. However, the tailed beasts used in the Ten-Tails' recreation transfered bits of their chakra into Naruto prior to Obito carrying out the process as the Ten-Tails sees them supporting the human in spirit as they all have recognised him as the one that the Sage of the Six Paths foretold. After Obito became its jinchuriki, the Ten-Tails assumes its true form to enact its host's desire while draining the chakra of those can it grasps in its branches. Eventually, through the combined effort of the Allied Shinobi Forces and Taka, all of the sealed tailed beasts were extracted from Obito's body. Shukaku: Shukaku, more commonly known as the One-Tail, is a tailed beast that was last sealed within Gaara of Sunagakure after being sealed in two other hosts. It was captured by Deidara, then extracted and sealed by Akatsuki, only to be released later on by Gaara. Matatabi: Matatabi, more commonly known as the Two-Tails, is a tailed beast that was sealed within Yugito Nii of Kumogakure. It has been captured by Hidan and Kakuzu, then extracted and sealed by Akatsuki. It was later resealed into a reincarnated Yugito during the Fourth Shinobi World War. Isobu: Isobu Isobu, more commonly known as the Three-Tails, is a tailed beast that was formerly sealed in Yagura of Kirigakure, after being sealed in Rin Nohara as part of Kirigakure's plan to attack Konohagakure. It has been captured by Deidara and Tobi, then sealed by Akatsuki. It was later resealed into a reincarnated Yagura during the Fourth Shinobi World War. Son Goku: Son Goku, more commonly known as the Four-Tails, is a tailed beast sealed within Roshi of Iwagakure. It was captured by Kisame Hoshigaki, then extracted and sealed by Akatsuki. Son was later resealed into a reincarnated Roshi during the Fourth Shinobi World War. Kokuo: Kokuo, more commonly known as the Five-Tails, is a tailed beast sealed within Han from Iwagakure. It has been captured, extracted, and sealed by Akatsuki. In the anime, Kokuo is indicated to have been one of the two tailed beasts that Akatsuki captured before the start of Part II. It was later resealed into a reincarnated Han during the Fourth Shinobi World War. Saiken: Saiken, more commonly known as the Six-Tails, is a tailed beast sealed within Utakata of Kirigakure. It has been captured by Nagato in the anime, then extracted and sealed by Akatsuki. It was later resealed into a reincarnated Utakata during the Fourth Shinobi World War. Chomei: Chomei, more commonly known as the Seven-Tails, is a tailed beast sealed within Fu from Takigakure. It has been captured, extracted, and sealed by Akatsuki. In the anime, Chomei is indicated to have been one of the two tailed beasts that Akatsuki captured before the start of Part II. It was later resealed into a reincarnated Fu during the Fourth Shinobi World War. Gyuki: Gyuki, more commonly known as the Eight-Tails, is a tailed beast sealed within Killer B of Kumogakure after Fukai, Fukai's uncle and Fukai's father failed before him. Kurama: Kurama, more commonly known as the Nine-Tails, is a tailed beast sealed within Naruto Uzumaki. Kurama was first sealed into Mito Uzumaki after the battle at the Valley of the End, then into Kushina Uzumaki after Mito's death. During its attack on Konoha, Minato Namikaze sacrificed his life by splitting the fox's chakra into two: sealing the Yin half within himself and sealing the Yang half within Naruto. Shinju: The Shinju, more commonly referred to as the Ten-Tails, is the primordial entity and the original tailed beast tied to the legend of the Sage of the Six Paths. Its chakra was divided into the nine tailed beasts and its body sealed into what would be the moon, by the Sage at the end of his life. Considered to be the progenitor of the world, its revival would herald the end of it. Jinchuriki: Shukaku: Hyuga Itsuki Matatabi: Isobu: Son Goku: Kokuo: Saiken: Chomei: Gyuki: Kurama: Kaminari Kaito